Birth control lets a man and woman have sexual intercourse but makes pregnancy less likely.

During intercourse, a man places his penis within a woman's vagina and moves it in and out while the woman moves her hips. The vagina is warm and soft, and it places pressure on the man's penis. These sensations, combined with the in-and-out movements, stimulate the penis, which causes the man to have an orgasm. During orgasm, the man's penis spasms and experiences a series of rhythmic contractions during which he ejaculates (releases semen into the vagina). The semen can make the woman pregnant. Because intercourse is usually very enjoyable, men and women often want to have intercourse a lot more often than they want to have a baby. Birth control lets them have intercourse while greatly reducing the chances of the woman getting pregnant.

People may use birth control for several reasons. Perhaps a man and woman wish to have only a few children so they will have enough money to give those children good food, clothes, and education. More children might mean less for each child, so the parents use birth control to limit the number of children they have. Or maybe a man and woman do not want any children at all in order to focus on their own lives, jobs, or each other. Other couples may use birth control to make sure that they do not have too many children in too short a time, an idea that is called "spacing" their children. This may help them take better care of their children. Still another reason is that a young couple may not be able to afford having a baby until they are older and have more money or better jobs. This may be especially true of younger people who are still in school and probably not married. By using birth control, the couple can grow closer and strengthen their relationship by having sexual intercourse frequently so that when they are ready to have a baby their relationship is strong and stable. In most of these cases the man and woman want to have sex to be close, to feel good with each other, and to make their relationship stronger. Contraception lets them have intercourse while greatly reducing the chances of a pregnancy.

Birth control may be used by married couples, or by couples who live together but are not married, or by a man and woman who are engaged, or by a couple who are merely boyfriend and girlfriend, or even by single people who are not in a relationship at all but who may have casual sex with others.

There are many types of birth control. Some of these have been done for a long time, but many of them were only discovered in the last eighty years. Each type of birth control has advantages and disadvantages. Another word for a type of contraception is a method.

A barrier is something that stands between two things. So barrier methods stand between the sperm and the ovum (egg). Some barrier methods help prevent many sexually transmitted diseases (STDs):

Condoms

Condom – this is the oldest barrier method. A condom is a thin tube (often made of latex) that the man puts over his penis. This keeps the sperm from getting to the egg. Condoms are also called rubbers.

Female condom – this is like a condom, but it goes in the woman's vagina.

Contraceptive sponge – this is a sponge that is filled with spermicide (a substance that kills sperm) and is put in the woman's vagina over the cervix.

Barrier methods can be easy to use and have few side effects (bad things that happen if you take a medicine). Some of them can be bought without a doctor's prescription. Since they are easy to get and can help stop disease from spreading from one partner to the other, they are popular with younger couples or those who are early in a relationship. But sometimes they can be messy or interfere with the pleasure and sensation of sex.

These can only be used by women. Doctors are trying to find a way to use hormonal methods for men. Hormonal methods change the woman's reproductive cycle in different ways so that it is safe for her man to ejaculate inside her.

Birth Control Pills

Birth Control Pills – these are pills that a woman takes every day that make her stop ovulating (making eggs). They usually have both female hormones estrogen and progesterone in them. Some have only progesterone. Birth control pills are a very popular type of birth control because of how effective and easy to use they are. A woman who uses birth control pills is often said to be "on the Pill."

Birth Control Patch – this is a small and thin object that is put on the woman's skin and stays there. Hormones in the patch go into the skin and into the woman's body. This makes her not ovulate.

Emergency contraception pill – also called the morning-after pill. This is a medicine that is taken after sex that makes the woman less likely to get pregnant. It is best if used very soon after sex. The longer after sex it is taken, the less effective it is. It is recommended to be taken no more than 48 hours after the event. After this time, the pill no longer works well.

Implants – these are objects that are put under the woman's skin and stay there for years. They slowly put hormones into her body and make her not ovulate. These only have progesterone in them (not estrogen).

Injections (shots) – this is where a doctor or nurse gives the woman a shot with a needle every three to six months depending on the type of injection. They inject a progesterone hormone that makes the woman not ovulate.

Rings - a soft plastic ring that is placed inside the vagina. The hormones in the ring go into the woman's vagina and into her body to prevent her from ovulating. The ring cannot be felt during sex and one ring lasts for up to three months.

Hormonal birth control is extremely effective if it is used in the right way. Many hormonal birth control methods also make women's menses shorter and with less bleeding, which most women like. And unlike barrier methods, hormonal methods do not interfere with sex. When a woman is using hormonal birth control, she and her man are usually not even aware of it during intercourse, which seems and feels very natural. The couple can have sex at any time they wish; they don’t need to interrupt foreplay to put birth control in place, and they can feel the physical sensations and emotional closeness of intercourse without interference from a make or female condom. Unlike coitus interruptus (see below), when a woman is on the Pill or using some other form of hormonal birth control, intercourse usually ends with her man reaching orgasm while inside the vagina, which both the man and woman usually find very pleasurable. For all of these reasons, hormonal methods are very popular, especially with women who are married or in steady relationships who are having sex often.

Hormonal birth control methods have some slight risks for side effects. They may make a very small increase in the risk of blood clots in the lungs, strokes, heart attacks, and breastcancer. Most of these risk are small. Some women may experience mood swings, weight gain, or loss of sex drive. Sometimes, but rarely, these side effects are serious enough to make a woman decide to stop using hormonal birth control.

This is when a man or woman has surgery to make them not able to make babies.

Men can get a vasectomy. This is a small surgery where the tube that carries sperm from the testicles is cut.

Women can get tubal surgeries. These are ways that the fallopian tubes are cut or clipped so that eggs cannot go down them to the uterus. (The fallopian tube is the tube that carries the egg from the woman's ovary).

Sterilization is extremely effective, and they allow a man and woman to have intercourse that seems and feels very natural. But sterilization does involve surgery, which can cost more than other types of contraception and can be unpleasant, and unlike other methods it is very hard to reverse if a couple changes their minds and want to have children later.

Other surgeries will make a woman sterile (not able to get pregnant). These are not done only for contraception, but they are done for other reasons.

These have been used for a very long time. They were used before modern medicine. Some of them were used before scientists even discovered how reproduction (making babies) happens.

Coitus interruptus (sometimes called "withdrawal" or "pulling out"– when the man takes his penis out of the woman's vagina before semen (liquid that has sperm in it) comes out. This is not a good method of birth control because the fluid that comes out before semen comes out also has sperm in it, and because if the man's semen is close to the woman's vagina, she can still get pregnant. Also, because the man's instinct is to stay inside the woman's vagina when he ejaculates, there is always a danger that he may not withdraw his penis in time. Even when it works, this can be a very frustrating method for both the man and woman because it interrupts their closeness and good feelings at the climax of intercourse.

Non-penetrative sex, non-vaginal sex – sex without putting the man's penis in the woman's vagina. This is more effective than coitus interruptus, but it can still be risky if the man ejaculates on or near the woman, and it can also be frustrating for the couple not to be able to have intercourse.

Abstinence – not having sex. If a couple can practice this correctly, it is completely effective at preventing pregnancy. It is free and does not require the help of a doctor. But it can be very frustrating for a man and woman to not be able to have intercourse.

Many methods can reduce the risk of STDs, but only abstinence is 100% effective.

This means a man and a woman practice abstinence (not having sex) when the woman is fertile. When the woman is not fertile, she will not get pregnant when she has sex.

Natural family planning: this is also called 'fertility awareness'. For this method, a woman reads her temperature (how warm her body is) in the morning, or she reads her cervical mucus (liquid that comes out of her vagina). Using the temperature or the cervical mucus, there are rules that say when the woman is fertile and not fertile.

Rhythm method: this is where a woman records the number of days between her menses (the time when she bleeds). The woman is most likely to be fertile in the days right between her menses. For some women, the math does not work. They get pregnant when the math says they are less fertile.

This is when a woman is breastfeeding (using her breasts to make milk for her baby). There are certain rules the woman can use to know if she is not fertile. Chances that this method will fail are about 10% (which means 10% chance she can get pregnant)

Induced abortion (sometimes called just abortion) is when a doctor gives a pregnant woman a medicine or does a surgery to stop the pregnancy. Some people do not call abortion a kind of contraception. This is because contraception means preventing pregnancy, but abortion is stopping a pregnancy that has already started.

Abortion is not a good birth control method. If a woman does not want to get pregnant, other methods are more safe and inexpensive (cost less money). So many doctors who do abortions for women help women find a better way to not get pregnant the next time.

Some religions do not like contraception. Some of them teach that contraception is a sin.

Religions ideas about contraception:

Catholicism – almost all types of birth control are a sin (except Natural Family Planning or abstinence).

Protestantism – most Protestant churches believe birth control is not a sin.

Islam – most schools of thought believe that some methods of birth control are not a sin. This is not applicable to sterilization, birth control due to financial hardship, or methods that deprive a woman of her right to sexual satisfaction.

Judaism – there are many different beliefs in Judaism about birth control, but even the most conservative types of Judaism allow it if the woman will get sick if she gets pregnant.

Religious beliefs that contraception is a sin also keep people from doing safe sex. Some groups who are opposed to this belief say it is dangerous in places where there is a lot of HIV and AIDS, because condoms make people much less likely to get HIV, but at the same times many feel that they can practice extra marital sex since they are "safe" from HIV/AIDS.